In general, a photosensitive composition containing a compound having an ethylenically unsaturated bond and a photopolymerization initiator can be cured by being irradiated with an active energy ray. Accordingly, the photosensitive composition has been used in various applications such as a photocurable adhesive, a photocurable ink, a photosensitive printing plate, and various photoresists.
For example, oxime ester compounds each containing a carbazole skeleton have been known as photopolymerization initiators (for example, Patent Literatures 1 to 3). Those compounds have been suitably used because the compounds each have excellent sensitivity to an active energy ray. However, the development of a photopolymerization initiator that is more excellent in sensitivity to the active energy ray than those compounds are has been demanded. In addition, those compounds are susceptible to improvement in terms of solubility. Further, a photopolymerization initiator is used in various applications, and hence it has been demanded that the photopolymerization initiator have excellent performance concerning characteristics required in the respective applications in addition to high sensitivity to the active energy ray.
In addition, Patent Literatures 4 and 5 each disclose an oxime ester compound having a fluorene skeleton. However, the literatures do not have any specific disclosure concerning, for example, a method of synthesizing the compound, and whether the compound is useful as a photopolymerization initiator is unclear.